Charles james dobbs



(No Model.)

0. J. DOBBS.

MANUFAGTURE OP PAVING BLOCKS FROM FURNACB SLAG, ne, No. 300,580.

Patented June 17, 1884.

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N. FZTERP Phorouxhagnpmf, www. D. C.

"Umfrne STATES PATENT Ormea, i'

CHARLES JAMES DOBBS, OF MIDDLESBROUGH, COUNTY OF'YORK, ENGLAND.

MANUFACTURE OF PAVING-BLOCKS FROM FURNACESLAG, 86C.

SPECIFICATION forming part f Letters Patent NO, 300,580, dated June 17, 1884-.

Application filed January 23,1884. (Xo model.)V Patented in England August 9, 1883, No. 3,870, and in Belgium January 3, 1834.

io specification.

In the manufacture of pavingblocks from slag as at present carried out the slag is run directly from the blast-iurnace into iron molds arranged round a turntable, and when the mass is just set the blocks are allowed to fall out ofthe molds and are put into a kiln of large dimensions previously heated by nre, where they are allowed to remain about fifteen or twenty hours, so as to become thoroughly 2o annealed, whereupon the kiln is opened and the bricks are allowed to cool gradually.

New, my present invention has for its object to obviate the expense consequent upon having to heat the large kilns in the rst instance;

and it consists in effecting the perfect annealing of the blocks solely by their own initial heat-that is to say, without any preliminary tiring of the kilnmthis being rendered possible by constructing the kilns in a different 3o manner to that heretofore employedf-namely,

instead of constructing them of one large chamber requiring a large number of blocks to fill it, I construct them with a series of separate chambers of smaller size, each of which is charged separately with a moderate number of blocks, and which are, by preference, made to communicate with each other by means of fines provided with regulating-slides, so that the surplus heat given off from the blocks in the 4o one chamber may be led off to another chamber, in order to heat it to a certain extent before receiving its charge of blocks. By employing thisy arrangement I have found from' experiment that the heat retained by the central portion of the blocks, which is still in a more or less liquid state when they are introduced into the kiln, is suflicient to effect the perfect annealing ofthe blocks without the use of additional iiring, as such central heat is 5o 'gradually conveyed by conduction to the more or less cooled outer portion of the block, thus rendering the temperature of the block uniform throughout, in which condition it is allowed to cool down gradually.

Although Iprefer to construct thekiln with groups of small chambers, as described, yetin cases where only a limited ground-space is available near the blast-furnace, I construct the said small annealing chambers or kilns separately, and in some cases I mount them upon carriages, so that each chamber may be run near to the blast-furnace to receive its charge, and be then removed to a locality where sutlicient ground-space is available. By the use of such small-sized kilns or anneal ing-chambers, whether fired or movable, I am also enabled to utilize the slag from smaller furnaces than those to which the process has hitherto alone been applied with advantage. The said movable kilns or annealingchambers may also be used with advantage to supplement the fixed kilns at blast-furnaces that are of such large dimensions that the whole of the available slag-supply 'cannot be utilized by iiXed kilns ou account of the limited space near to the blast-furnace.

rllhe accompanying drawings show, by way of example, two constructions of annealing kilns or chambers for carrying out my said,

invention.

Figure l shows a part front elevation and part section oi' a series of anuealingchambers, A A, arranged side by side, and Fig. 2 shows a longitudinal section of one of the chambers.

The chambers A are formed of brick-work with an iron casing, and they are closed in front by two folding doors, B I3, lined with nre-brick, secured by a bar, O, and having formed in them two openings, D D, closed by slabs E E. The chambers are also provided with openings F at top, closed by slabs G, and in the partition-walls are formed other openings, H, provided with a slide, I, on raising whichthe one chamber can be made to communicate with the contiguous one.

The slag having been run into the iron molds in the ordinary manner, and the blocks having become set in the molds, the latter are at once charged into the chambers, iirst through the lower opening, D, and afterward through the upper one. The chamber having been iilled,

the openings D are closed, whereupon the ICO . by radiation into the next chamber, so as to greater heat contained in the central portion of the blocks will be gradually conveyed by conduction to the outer surfaces, thereby rendering the block of a perfectly uniform temperature throughout. In this condition the blocks are allowed to remain about twelve hours and then to cool down gradually, whereby they become perfectly annealed Without any additional heating of the chambers being required beyond that which is obtained by radiation from the blocks themselves. During the cooling the slide I may be opened, so as to allow a portion of the heat given off to pass heat this to a certain extent before receiving its charge of blocks, and the openings F and doors E may also be opened more or less, if found necessary to accelerate the passage of heat. The blocks having cooled down to a sufficient extent, the doors B B are opened for the removal thereof, after which the chamber can be at once charged with fresh blocks. l

Fig. 3 shows an end elevation, and Fig. 4 a longitudinal section, of an annealing kiln or chamber mounted on wheels, so as to be capable of being brought near the blast-furnace to receive its charge of blocks, and then removed to a convenient place, as above described. VThe chamber A is here shown of cylindrical shape for obtaining the requisite strength without staying. It may, however, be made of a rectangular or otherconvenient shape. The construction of the chamber is otherwise the same as at Figs. l and 2, the parts being designated by the same letters of reference, and therefore requiring no further description.

Having thus described the nature of my invention and the best means I know of carrying it out in practice, vI clain1- l. The within-described method of manuthem therein, whereby the initial heat contained within the slag blocks without the aid of eXtraneously-applied heat will anneal the blocks, substantially as set forth.

2. In an annealing-kiln, the combination of a series of chambers located side by side and communicating with each other through suitable passages, whereby the heat evolved from the slag blocks in one chamber will pass into the communicating-chamber to heat the same, substantially as set forth. Y

3. A kiln for annealing slag blocks, composed of a series of chambers located side by side and communicating with each other through suitable passages and mounted upon wheels, substantially as and for the purpose set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses this 7th day of January, A. D. 1884.

CHARLES JAMES DOBBS. 

